The XOM class myClassX cannot be deserialized. Verify that the XOM library is set correctly.
javax.xml.bind.UnmarshalException
- with linked exception:
[javax.xml.bind.UnmarshalException: Unable to create an instance of myClassY
- with linked exception:
[java.lang.InstantiationException]]

1 reply

This might indicate that the class myClassX and myClassY are not compatible with JAXB. Some annotations might be missing.
Check if myClassX and myClassY are abstract classes or extend abstract classes.
To make abstract classes work with JAXB, add annotation @XmlSeeAlso to these abstract classes.